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  • Individualized High Density Electroencephalographic Source Imaging Technique in Presurgical Workup: Contribution to Surgical Strategy Making for Intractable Epilepsy Involving Mesial Temporal Lobe Str

    Final Number:

    Rui Feng MD PhD; Jie Hu; Jinsong Wu; Chengxin Ma; Liqin Lang; Bing Sun MD, PhD; Li Pan

    Study Design:

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2018 Annual Meeting

    Introduction: Localization-related epilepsy frequently involves mesial temporal lobe structures (MTLS), but sometimes presurgical workup is confusing since lack of clear structural lesions or inconsistency among multiple tools. We recently improved accuracy of EEG source imaging technique (ESI) and applied it in presurgical epilepsy workup. This study evaluates its contribution to surgical strategy of epilepsy involving MTLS.

    Methods: We included patients who underwent resective surgeries encompassing MTLS in this study. In addition to traditional tools, ESI was available in all cases. ESI was accomplished based on 256-channel high-density EEG and individualized finite difference method head models. Patients accepted either one-stage or staged resective surgeries (SEEG implantation+stage-two resective surgeries). Contributions of multiple tools to surgical strategies were evaluated.

    Results: Twenty-five cases with Engel I+II outcome after surgeries were included. ESI(80%) and MRI(76.0%) showed higher accuracy over ictal EEG(44.0%) and FDG-PET(56.0%) when defining resective scope as epileptogenic zone(p<0.05). In one-stage cases, ESI showed sources localized within MTLS region in 88.2% (same as MRI positive rate), while PET localized focally only in 64.7% (p<0.05). 62.5% staged cases showed complete concordance of ESI sources with SEEG findings, while for PET & MRI the ratio is 25% & 62.5%, respectively. ESI & PET contributed to SEEG plans in all, while MRI & ictal EEG contributed in 87.5% & 50%, respectively. In subtle lesional/MRI-negative cases, 62.5% showed subtle MRI lesions in MTLS firstly diagnosed as “negative”. ESI contributed more to detection/confirmation of these lesions (75% showed sources confined within MTLS region) than PET estimates (focally-localized in MTLS in 50%) (p<0.05).

    Conclusions: Non-invasive accurate ESI method described here is based on high density EEG and individualized head model, appearing contributable to surgical planning of epilepsy surgeries involving MTLS, by indicating MTLS region epileptic sources. This feature can help decide strategy of one-stage resective surgeries and SEEG implantation plans.

    Patient Care: By localizing the epileptogenic zone non-invasively, EEG source imaging technique can improve the efficiency of presurgical epilepsy workup, assisting traditional tools. It has features to help detect/confirm subtle/ ambiguous structural lesions in MRI, or even indicate sources in MRI negative cases, in order to help the decision making of one-stage resective surgeries without invasive evaluations. By these features, it can also help in SEEG implantation plan making by indicating epileptic regions including mesial temporal lobe structures.

    Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of EEG source imaging technique as an assistant tool in presurgical workup of intractable localization-related epilepsy involving mesial temporal lobe structures, 2) Discuss the features of this technique with high accuracy based on 256-channel high density EEG as well as individualized head models; 3) Learn the merits as well as pitfalls in using this technique in clinical work.

    References: [1] Brodbeck, V., Spinelli, L., Lascano, A.M., Wissmeier, M., Vargas, M.-I., Vulliemoz, S., Pollo, C., Schaller, K., Michel, C.M. and Seeck, M. Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients. Brain 2011; 134:2887-2897. [2] Holmes, M.D., Brown, M., Tucker, D.M., Saneto, R.P., Miller, K.J., Wig, G.S. and Ojemann, J.G. Localization of extratemporal seizure with noninvasive dense-array EEG. Comparison with intracranial recordings. Pediatr Neurosurg 2008; 44:474-479. [3] Feng, R., Hu, J., Pan, L., Wu, J., Lang, L., Jiang, S., Gu, X., Guo, J. and Zhou, L. Application of 256-channel dense array electroencephalographic source imaging in presurgical workup of temporal lobe epilepsy. Clin Neurophysiol 2016; 127:108-116. [4] Li, K., Papademetris, X. and Tucker, D.M. BrainK for Structural Image Processing: Creating Electrical Models of the Human Head. Comput Intell Neurosci 2016; 2016:1349851. [5] Pascual-Marqui, R.D., Esslen, M., Kochi, K. and Lehmann, D. Functional imaging with low-resolution brain electromagnetic tomography (LORETA): a review. Methods Find Exp Clin Pharmacol 2002; 24 Suppl C:91-95. [6] Song, J., Tucker, D.M., Gilbert, T., Hou, J., Mattson, C., Luu, P. and Holmes, M.D. Methods for examining electrophysiological coherence in epileptic networks. Front Neurol 2013; 4:55. [7] Russell, G.S., Jeffrey Eriksen, K., Poolman, P., Luu, P. and Tucker, D.M. Geodesic photogrammetry for localizing sensor positions in dense-array EEG. Clin Neurophysiol 2005; 116:1130-1140. [8] Luu, P., Caggiano, D.M., Geyer, A., Lewis, J., Cohn, J. and Tucker, D.M. Time-course of cortical networks involved in working memory. Front Hum Neurosci 2014; 8:4. [9] Yamazaki, M., Tucker, D.M., Fujimoto, A., Yamazoe, T., Okanishi, T., Yokota, T., Enoki, H. and Yamamoto, T. Comparison of dense array EEG with simultaneous intracranial EEG for interictal spike detection and localization. Epilepsy Res 2012; 98:166-173. [10] Michel, C.M., Murray, M.M., Lantz, G., Gonzalez, S., Spinelli, L. and Grave de Peralta, R. EEG source imaging. Clin Neurophysiol 2004; 115:2195-2222. [11] Ray, A., Tao, J.X., Hawes-Ebersole, S.M. and Ebersole, J.S. Localizing value of scalp EEG spikes: a simultaneous scalp and intracranial study. Clin Neurophysiol 2007; 118:69-79. [12] Yang, L., Wilke, C., Brinkmann, B., Worrell, G.A. and He, B. Dynamic imaging of ictal oscillations using non-invasive high-resolution EEG. Neuroimage 2011; 56:1908-1917. [13] Grova, C., Daunizeau, J., Lina, J.M., Benar, C.G., Benali, H. and Gotman, J. Evaluation of EEG localization methods using realistic simulations of interictal spikes. Neuroimage 2006; 29:734-753. [14] Holmes, M.D., Tucker, D.M., Quiring, J.M., Hakimian, S., Miller, J.W. and Ojemann, J.G. Comparing Noninvasive Dense Array and Intracranial Electroencephalography for Localization of Seizures. Neurosurgery 2010; 66:354-362.

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